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.\" and Copyright (c) 2017, Michael Kerrisk <mtk.manpages@gmail.com>
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
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.TH pthread_mutex_consistent 3 2024-05-02 "Linux man-pages 6.9.1"
.SH NAME
pthread_mutex_consistent \- make a robust mutex consistent
.SH LIBRARY
POSIX threads library
.RI ( libpthread ", " \-lpthread )
.SH SYNOPSIS
.nf
.B #include <pthread.h>
.P
.BI "int pthread_mutex_consistent(pthread_mutex_t *" mutex ");"
.fi
.P
.RS -4
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.RE
.P
.BR pthread_mutex_consistent ():
.nf
    _POSIX_C_SOURCE >= 200809L
.fi
.SH DESCRIPTION
This function makes a robust mutex consistent if it is in an inconsistent
state.
A mutex can be left in an inconsistent state if its owner terminates
while holding the mutex, in which case the next owner who acquires the
mutex will succeed and be notified by a return value of
.B EOWNERDEAD
from a call to
.BR pthread_mutex_lock ().
.SH RETURN VALUE
On success,
.IR pthread_mutex_consistent ()
returns 0.
Otherwise,
it returns a positive error number to indicate the error.
.SH ERRORS
.TP
.B EINVAL
The mutex is either not robust or is not in an inconsistent state.
.SH STANDARDS
POSIX.1-2008.
.SH HISTORY
glibc 2.12.
POSIX.1-2008.
.P
Before the addition of
.BR pthread_mutex_consistent ()
to POSIX,
glibc defined the following equivalent nonstandard function if
.B _GNU_SOURCE
was defined:
.P
.nf
.B [[deprecated]]
.BI "int pthread_mutex_consistent_np(const pthread_mutex_t *" mutex );
.fi
.P
This GNU-specific API, which first appeared in glibc 2.4,
is nowadays obsolete and should not be used in new programs;
since glibc 2.34 it has been marked as deprecated.
.SH NOTES
.BR pthread_mutex_consistent ()
simply informs the implementation that the state (shared data)
guarded by the mutex has been restored to a consistent state and that
normal operations can now be performed with the mutex.
It is the application's responsibility to ensure that the
shared data has been restored to a consistent state before calling
.BR pthread_mutex_consistent ().
.SH EXAMPLES
See
.BR pthread_mutexattr_setrobust (3).
.SH SEE ALSO
.ad l
.nh
.BR pthread_mutex_lock (3),
.BR pthread_mutexattr_getrobust (3),
.BR pthread_mutexattr_init (3),
.BR pthread_mutexattr_setrobust (3),
.BR pthreads (7)
